Seatylock Mason Bike U Lock - Patented Heavy Duty Anti Theft Diamond Secure ULock - Ultra Security Bicycle Safety Tool with Keys for City Electric or Mountain Bikes and Scooters

"Diamond" rated locks offer “the highest level of security” (tests include angle grinders)"The Best Bike Lock" ranks the SeatyLock Mason 220 with a "Sold Secure Diamond" for bicycle rating, its highest. And it's in the upper section of all this rating of locks for lightness, although it's not very light, weighing in at 1581 grams (3.48 lbs 3 lbs 7.8oz).*It's wider and a bit longer than other U-locks, so attaching the front wheel to the rear wheel and a post doesn't turn into a puzzle (Mason 220 is the widest SeatyLock offered).*3 keys - register your lock and identical keys can be purchased if you lose some.*double hatch lock (not just one side)*Opens and closes with a 90° key turn.*Reversible key (no need to look)*Key does not pull out when unlocked*Covered keyhole to keep dirt out*Spring loaded lock (doesn't fall apart when unlocked)But,*Heavy - OK for a commute or home use.*No attachment bracket - Need to put it in handlebar or rack bag (or backpack) For the price, it should include some sort of mounting bracket, but they're so many frame diameter sizes now that one size would not fit all.If you're looking for top security without going 2 to 3 times the weight, this one is rated at the top, even though it's still heavy. It's extra width, a plus for use, makes it a bit wide for a rear rack bag, but it will fit at an angle.It comes with a plastic ring that might be a key holder, but I haven't figured it out yet.If you're in a small town and ride a clunker and only leave it outside a store for a short time while shopping, this might be an overkill, but if you're in a city and have a nice bike or leave it parked all day while working, it might be worth it to haul this one around or lock it to the bike rack at work and not carry it.5 stars

The Mason 220 is rated Sold Secure Diamond which is the second highest rating for a U-lock. Even an angle grinder will require multiple cuts and likely more than one cutting disc to get through this lock. That requires effort so thieves are likely to pick another bike over yours.The Seatylock weighs 3lb 6oz and is fairly sizable. That makes it a bit bulky to carry. It has a small level of rattle, but is quieter than every other U-lock I own. Chances are you will need to carry this in a backpack or pannier. It doesn’t come with a frame mount, and the optional one you can purchase is the same strap design as most u-lock frame mounts…awkward and ugly.There’s a good amount of room inside the U-lock to go around a fat ebike downtube (see photo). All touch points are rubberized, so scratches are mostly avoidable. It comes with 3 keys and a 3year warranty.I usually have a pannier, so carrying the lock isn’t an issue for me. This my main lock now for my ebike. I also carry a gold rated folding lock as an extra hassle for thieves.There is one level up on u-locks that will resist angle grinders further, but the cost jumps quickly 2-3X as much as this lock. I think the Mason 220 is a good sweet spot. For price/protection.

this u lock is rock solid. it's soft to touch. the build quality is rock solid. I have confidence in this lock. overall, I m very happy with the quality of this U lock. the only minor issue is that it doesn't come with any holder/bike mount for this lock. so you either have to put it in the bag or figure out a way to hold it.

This is one serious heavy-duty bike lock that exceeds all the other many bike locks that I've used before, reassuring me that my bike is safe and secure.The extra weight might be an issue for serious riders who want to shed as much weight as possible for speed reasons, but my bike is relatively heavy already and I am not too concerned with carrying a little more weight. Security is more important to me than speed, so knowing my bike lock can stand up to thieves takes a weight off my mind.

It's worth the price if you have an expensive bike that you park in public areas. The sense of security is worth it. It's not as heavy as I thought it would be, but it's big and thick.

If you are looking for a light weight lock, this is not it. This lock feels heavy duty and it has some weight to it. Definitely inspires confidence and with the rubber covering it should hold up pretty well in bed weather. Comes with three keys which is nice for backup. Good size to lock a bike or a scooter, as well as other creative uses. I use it on a bike and it works really well. I wish some kind of a holder would be included with the lock so it can be mounted on a bike, but it looks like you have to purchase it separately unfortunately. I put it in a backpack and it works fine, but a bike attachment would be better.

Hard to say this is superior than other locks that are similar of different known brands. It is definitely better than those cheap versions and the locking mechanism is appropriate for the price. The key is made with a superior design and the u part of the lock should help protect agains shimming the internal locking mechanism.What ever you are locking, it will not be easily stolen.

What do I like:1) The magnets. Seriously. The base bar has magnets to hold the U in even before/after the lock is turned. This keeps it from falling out before you're ready and to keep it in while you turn the lock. Genious.2) Texture. The rubberized coating feels quality3) Lock keyway operation. Much better than other locks I have. The key inserts and turns smoothly. No fiddling. Even the shutter moves out and recloses easily.4) Diamond secure rating that is believable. The unique cross section of the U is believably more challenging to cut into. Fit and finish is consistent with an effective lock.

Das Bügel-Schloss macht einen richtig stabilen und extrem soliden Eindruck und fühlt sich mit seinen ca. 1,3 Kilogramm auch sehr wertig an. Es kommt leider ohne Clip zum Anbringen an den Rahmen. Auf jeden Fall ein Schloss dem man zutraut nie geknackt zu werden. 1A - sehr zufrieden damit.

When you need to make sure that your bike wont be going anywhere, when you really need to make sure that your ride will not get stolen.... this is what you are looking for.The strength is beyond words, I think if I had all the tools in the world and all the time to try to cut through it, I still would not have a chance of getting through it.The loop is advertised as being the widest you can get and why that is so important is because most of the locks like this have a more narrow loop and that means you cant get a lot of wider bicycle frames in the regular locks and that is a big problem if you need to lock your bike up properly.This lock however is able to handle any size bike, even fat bikes. The room is perfect and the space between the bottom bar and the loop really helps to make sure you can keep your bike safe.The lock is reviewed as being the best on the market by so many sites, its just amazing.

It's not clear what the security scale is on which it scores 20 and has diamond status - it isn't a standardised rating system in itself, but the manufacturers do indicate that it is aligned with the Sold Secure system, which is an independent and widely recognised UK-based rating system for security products. According to SeatyLock's website their own security rating system ranges from 1 to 18, so we're in Spinal Tap territory here with 20! It is also "Ice Spray certified" - presumably meaning that it will be safe from attempts to freeze the lock with compressed air or liquid nitrogen to make it brittle - and seems to be recommended by the Danish Cyclists' Federation. All in all, I am reassured that it is indeed of a high standard of security.It is sturdy, and comes with a double deadbolt, ie one on each arm of the U. What it doesn't come with (and the only reason for taking one star away) is a means of securely attaching it to the crossbar or downtube while not in use. There is no indication of what mounting brackets might be suitable for doing so, though the Product Info does say "Mounting Bracket Sold Separately"). I can only assume that a SeatyLock mounting bracket like this one would be compatible. In the meantime I've just been keeping it in my pannier.I registered the keys with Seatylock so in theory I should be able to get a copy should I ever lose all three keys. It also triggers a 3 year warranty. To date though I have not received any acknowledgment confirming either the key registration or the 3 year warranty.This lock might seem expensive, but if your bike is worth keeping then this is worth investing in.

This is an expensive lock, but for a diamond rated one it's actually really good value. You can easily spend double the price of this one for an equivalently secure bike lock. For bang for the buck you can really stop reading here as you won't get a better lock for this price.It's also a really well thought out lock. It's not self-locking, so you need to turn the key to lock the lock. I prefer this, as I have in the past cheerfully clicked my lock closed only to realise I've left the keys at home. The locking mechanisim is really smooth and clicks shut crisply. You won't be fumbling about in the dark trying to workout what isn't quite lined up somewhere to get your bike safe. The lock is covered in a silcone material whiich is nicely tactile and easy to hold and grip as well, and the U-part is slightly wider than some locks. All in all this is a really easy lock to use, both to lock your bike and unlock it.Both ends of the U-section are secured, so anyone cutting the lock will need to do so in two places to get the lock free. The locking part is very beefy and while nothing is immune to power tools it would take some effort and time to get through this one, encouraging thieves to look for easier pickings.It's not too heavy and is comfortable to carry in a satchel. There is no bike carrier supplied which keeps the price down and a bonus if you never use them anyway, like I don't. You can buy one seperately if you want one though. It comes with two keys, and you can register the lock so you can order more if you need/want to.It's a really, really good lock. Quick and easy to lock up with, reasonably lightweight for a lock of this solidity, tremendously good value, and it looks pretty cool too.Excellent lock, highly recomended.

A high quality robust shackle lock that has the look and feel of a serious deterrent. It's a solid bit of kit with a wide fit so I've had no issues securing Ebikes when required. It's well sealed and protects against the elements and the locking mechanism functions well overall.Can't fault it so I'm happy to recommend it.